Field of Invention
The invention is related to the structure of an implant that can be placed inside the thyroid cartilage of a human or animal larynx (voice box) in order to medialize the vocal folds (vocal cords). The surgical procedure is called a thyroplasty and is well established. It is used to treat vocal fold paresis, vocal fold paralysis, and other conditions that cause glottic insufficiency (failure of the vocal folds to approximate completely) which result in dysphonia (vocal weakness, breathiness, hoarseness and other symptoms). The thyroplasty implant of the subject invention is unique and an improvement over the prior art. The invention may be constructed in various sizes as required to serve its purpose.
Description of Prior Art
A thyroplasty is a surgical technique(s) which changes the human voice by altering single or multiple structures of the larynx. By altering the position and tension of the vocal folds, the procedure may create a stronger sounding voice and alter the tonal output of the vocal folds. A thyroplasty procedure involves placing an implant within or against the vocal folds or surrounding tissue in order to change the tension and positioning of the vocal folds which in turn affects the tonal output of the voice.
Thyroplasty implants of the prior art exist in various forms. The original thyroplasty devices were individually hand carved for each patient out of silastic or a similar material. This approach is still used widely. The second approach was pre-formed thyroplasty implants that do not require carving. They are available in several sizes and are made of various material including silastic and hydroxylapatite. They are also still in use. The third approach was to replace an implanted block with a ribbon of Gore-Tex, placement and contour of which can be adjusted easily during the process of insertion. All thyroplasty implants are inserted into the larynx.
Thyroplasty implants must be adjusted to achieve the desired tonal output. Accordingly, when inserted, the implant may need to be reshaped and cut in order to change the shape and size of the implant. The change in the shape and size of the implant alters the amount of pressure placed upon the vocal folds. Similarly, the pressure may be adjusted by changing the implant with another modified implant of the different size and shape. Even under regular present day methods, implant changes must be accomplished by a surgical procedure.
The implants are also subject to late failure because of displacement or because of changes in the patient's anatomy over time. When thyroplasty revision is necessary (a common occurrence), under present day treatment methods, the revision must be accomplished by returning to the operating room and either modifying the existing device or removing and replacing it. All commonly used existing devices present difficulties in effecting fine adjustments to optimize voice quality intraoperatively. These all require an additional operation if revision is needed, and no existing implants may be adjusted after implantation for “fine tuning” the voice without surgery.
Hoffman, in U.S. Pat. No. 8,613,767, attempts to provide an adjustable laryngeal implant which provides for a displacement member which may be varied in size upon insertion of a liquid or other substance into an interior chamber of the displacement member. The displacement member must be fixed to a mount with is attached to thyroid cartilage to prevent the displacement member from moving out of position. The displacement member is then “adjusted” by filling the displacement member through an inlet port connected to flexible tubing connected to a fluid reservoir. A syringe may be used to fill the fluid reservoir. When proper adjustments have been made, the fluid tubing is cut and the inlet port must be sealed.
However, Hoffman has many disadvantages which render the invention difficult to use, and Hoffman fails to overcome many of the limitations of the prior art. The Hoffman device cannot be maintained indefinitely with flexible tubing attached, and accordingly, the flexible tubing used to fill the bladder must be removed. Future adjustments of the device require additional surgeries. Further, the Hoffman device only contains a single displacement member which fails to provide a sufficient degree of adjustment control. The present invention overcomes the limitations of Hoffman by providing for a device which provides for greater means of adjustment during initial surgery and a means of adjustment post-operatively using minimally invasive techniques. Therefore, it is the object of the present invention to provide a device that can be adjusted easily intraoperatively, and that can be adjusted postoperatively as needed over time, without the need for additional surgery.